The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
A hybrid electric vehicle uses both an internal combustion engine and a battery power source. The hybrid electric vehicle efficiently combines the torque of the internal combustion engine and the torque of a motor.
Hybrid electric vehicles may be categorized as either a hard type or a mild type according to a power sharing ratio between the engine and the motor. In the case of the mild type of hybrid electric vehicle (or a mild hybrid electric vehicle), a mild hybrid starter & generator (MHSG) configured to start the engine or generate electricity according to an output of the engine is used instead of an alternator. In the case of the hard type of hybrid electric vehicle, a driving motor for generating driving torque is used in addition to an integrated starter & generator (ISG) configured to start the engine or generate electricity.
The mild hybrid electric vehicle does not provide a driving mode in which torque of the MHSG is used for the main driving torque, but the MHSG may assist the torque of the engine according to the running state of the vehicle and may charge a battery (e.g., a 48 V battery) through regenerative braking. Accordingly, the fuel efficiency of the mild hybrid electric vehicle may be improved.
U.S. Pat. No. 8,936,531, which is a related art, may determine whether a current position of a vehicle is in a dangerous area when a driver of the vehicle changes a gear from a drive mode to another mode, and may immediately restart an engine when it is determined that the current position of the vehicle is in the dangerous area.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the present disclosure, and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art.